The book provides a detailed introduction to a major debate in bioethics, as well as a rigorous account of the role of conscience in professional decision-making. Exploring the role of conscience in healthcare practice, this book offers fresh counterpoints to recent calls to ban or severely restrict conscience objection. It provides a detailed philosophical account of the nature and moral import of conscience, and defends a prima facie right to conscientious objection for healthcare professionals. The book also has relevance to broader debates about religious liberty and civil rights, such as debates about the rights and duties of persons and institutions who refuse services to clients on the basis of a religious objection. The book concludes with a discussion of how to regulate individual and institutional conscientious objection, and presents general principles for the accommodation of individual conscientious objectors in the healthcare system. This book will be of value to students and scholars in the fields of moral philosophy, bioethics and health law.